The approaches described in this section could be pursued, but are not necessarily approaches that have been previously conceived or pursued. Therefore, unless otherwise indicated herein, the approaches described in this section are not prior art to the claims in this application and are not admitted to be prior art by inclusion in this section.
Today, dialog systems are widely used in the information technology industry, especially as mobile applications for wireless telephones and tablet computers. Generally, a dialog system refers to a computer-based agent having a human-centric interface for accessing, processing, managing, and delivering information. Dialog systems are also known as chat information systems, spoken dialog systems, conversational agents, chatter robots, chatterbots, chatbots, chat agents, digital personal assistants, and automated online assistants, to name a few. All these terms are within the scope of the present disclosure and referred to as a “dialog system” for simplicity.
Traditionally, a dialog system interacts with its users in natural language to simulate an intelligent conversation and provide personalized assistance to the users. For example, a user may generate requests to the dialog system in the form of conversational questions, such as “Where is the nearest hotel?” or “What is the weather like in Arlington?”, and receive corresponding answers from the dialog system in the form of an audio and/or displayable message. The users may also provide voice commands to the dialog system so as to perform certain functions including, for example, generating e-mails, making phone calls, searching particular information, acquiring data, navigating, providing notifications and reminders, and so forth. Thus, dialog systems are now very popular and are of great help, especially for holders of portable electronic devices such as smart phones, cellular phones, tablet computers, gaming consoles, and the like.
Historically, dialog systems, and especially spoken dialog systems, require a user to activate a dialog system before he makes a request. It is obvious that otherwise dialog systems acquire all spoken words made by the user, which will lead to the dialog system overloading, excessive use of computing resources, inaccuracy of dialog system responses, and so forth. Accordingly, users need to manually activate dialog systems every time they want to make a request. This may be very annoying and inconvenient for the users. Additionally, the need for manual reactivation of dialog systems does not allow the dialog systems to be user friendly and keep human-like speech conversations, which significantly limits their application.